Sound travels about 4 times faster in water than in air.
408
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
The left ear is more responsive to words of love and emotion whispered into it than the right.
40
Pumice is the only rock that floats on water.
14
Brass doorknobs automatically disinfect themselves in about 8 hours.
18
At room temperature, the average air molecule travels at the speed of a rifle bullet.
55
Stannous fluoride, which is the cavity fighter found in toothpaste is made from recycled tin.
65